阅读说明：本技术 液压式发动机制动系统 (Hydraulic engine braking system ) 是由 褚志强 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种液压式发动机制动系统,包括支撑框架,支撑框架上安装有制动控制装置和制动活塞装置,制动控制装置包括滑动安装在支撑框架内的密封活塞,支撑框架内位于密封活塞的两侧分别连通有单向阀总成与限压阀总成,所述支撑框架上设有制动启动油道、制动充油油道、释放泄压油道,密封活塞在支撑框架内往复运动连通与切断释放泄压油道；制动活塞装置包括竖向滑动安装在支撑框架内的制动活塞,制动活塞的底端伸出支撑框架外与制动销接触,制动活塞的顶部设置有与制动充油油道和释放泄压油道连通的制动孔腔；本发明具有充油稳定、响应速度快、制动行程稳定可靠、便于手工直接测量、可减少运动摩擦的等优点。(The invention discloses a hydraulic engine braking system, which comprises a supporting frame, wherein a braking control device and a braking piston device are installed on the supporting frame, the braking control device comprises a sealing piston which is installed in the supporting frame in a sliding manner, two sides of the sealing piston in the supporting frame are respectively communicated with a one-way valve assembly and a pressure limiting valve assembly, a braking starting oil duct, a braking oil charging oil duct and a releasing pressure relief oil duct are arranged on the supporting frame, and the sealing piston reciprocates in the supporting frame to be communicated with and cut off the releasing pressure relief oil duct; the brake piston device comprises a brake piston vertically and slidably arranged in the support frame, the bottom end of the brake piston extends out of the support frame and is in contact with the brake pin, and the top of the brake piston is provided with a brake hole cavity communicated with the brake oil-filled oil duct and the release pressure-relief oil duct; the invention has the advantages of stable oil filling, high response speed, stable and reliable braking stroke, convenient manual direct measurement, reduced motion friction and the like.)

1. Fluid pressure type engine braking system, including braced frame, last brake control device and the braking piston device of installing of braced frame, its characterized in that: the brake control device comprises a sealing piston arranged in the supporting frame, a one-way valve assembly and a pressure limiting valve assembly are respectively communicated with two sides of the sealing piston in the supporting frame, a sealing piston resetting device is arranged between the sealing piston and the pressure limiting valve assembly, a brake starting oil duct is communicated between the one-way valve assembly and the sealing piston, a brake oil charging oil duct is communicated between the one-way valve assembly and the brake piston device, a release pressure relief oil duct is communicated between the brake piston device and the pressure limiting valve assembly, and the sealing piston reciprocates in the supporting frame to be communicated with and cut off the release pressure relief oil duct;

The brake piston device comprises a brake piston vertically and slidably mounted in the support frame, the bottom end of the brake piston extends out of the support frame and is in contact with a brake pin, the top of the brake piston is provided with a brake hole cavity communicated with the brake oil charging oil passage and the release pressure relief oil passage, and a brake piston resetting device is arranged between the lower part of the brake piston and the support frame.

2. The hydraulic engine braking system of claim 1, wherein: a piston starting cavity and a piston oil storage cavity are respectively arranged on two sides of the sealing piston, the piston starting cavity is communicated with the one-way valve assembly, and the piston oil storage cavity is communicated with the pressure limiting valve assembly; the brake starting oil duct is communicated with the one-way valve assembly and the sealing piston through the piston starting cavity, the release pressure-relief oil duct is communicated between the brake hole cavity and the piston oil storage cavity, and the sealing piston reciprocates in the piston starting cavity to be communicated with and cut off the release pressure-relief oil duct.

3. The hydraulic engine braking system of claim 1, wherein: the check valve assembly comprises a check ball valve which connects and disconnects the piston starting cavity and the brake oil charging oil duct, a check valve return spring is arranged at the top end of the check ball valve, and the check valve return spring is connected to the supporting frame through a check valve plug.

4. the hydraulic engine braking system of claim 1, wherein: the pressure limiting valve assembly comprises a pressure limiting valve body fixedly mounted on the supporting frame, a pressure limiting ball valve for pressure relief and pressure maintaining is mounted on the pressure limiting valve body, a pressure limiting return spring for controlling the pressure limiting ball valve to open and close is arranged at the bottom end of the pressure limiting ball valve, and a pressure relief hole is formed in the pressure limiting valve body.

5. The hydraulic engine braking system of claim 1, wherein: the sealing piston resetting device comprises a sealing piston resetting spring connected between the sealing piston and the pressure limiting valve assembly.

6. The hydraulic engine braking system of claim 1, wherein: an adjusting bolt is installed at the top end of the supporting frame in a threaded mode, and the bottom end of the adjusting bolt is installed in the braking hole cavity; and an antifriction device is arranged on the sliding peripheral surface of the brake piston matched with the support frame.

7. The hydraulic engine braking system of claim 6, wherein: the friction reducing means includes a plurality of annular grooves provided on a sliding outer peripheral surface of the brake piston.

8. The hydraulic engine braking system of claim 6, wherein: the upper part of the brake piston is provided with a piston sliding part in sliding fit with the support frame, the top end of the piston sliding part is provided with a piston limiting cover which surrounds the brake cavity, the piston limiting cover is provided with a piston oil inlet channel which communicates the brake cavity with the brake oil charging oil duct, and the lower end of the brake piston is provided with a piston rod which extends out of the support frame.

9. The hydraulic engine braking system of claim 8, wherein: the brake piston resetting device comprises a return spring baffle arranged at the bottom of the supporting frame, a brake return spring used for driving the brake piston to reset is arranged between the return spring baffle and the brake piston, and the brake return spring is sleeved outside the piston rod, and two ends of the brake return spring are respectively abutted against the return spring baffle and the piston sliding part.

10. The hydraulic engine braking system of claim 6, wherein: the upper part of the adjusting bolt is fixed on the supporting frame through a locking nut, a bolt adjusting groove which is beneficial to screwing in and screwing out is formed in the top end of the adjusting bolt, a limiting boss which is installed in the braking hole cavity is arranged at the bottom end of the adjusting bolt, and the outer diameter of the limiting boss is smaller than the inner diameter of the braking hole cavity; the top end of the piston limiting cover is provided with a limiting hole which limits the limiting boss in the braking hole cavity, and the limiting hole is a round hole or a long hole.

Technical Field

The invention belongs to the technical field of engines, and particularly relates to a hydraulic engine braking system.

background

the total mass of modern automobiles is getting larger and larger, the speed of the modern automobiles is getting higher and higher, and the rolling resistance, the wind resistance and the internal friction loss of the modern automobiles are getting smaller and smaller, which means that the self-deceleration capacity of the modern automobiles is reduced; meanwhile, due to the increase of the total mass of the vehicle, the braking requirement of the vehicle under the condition of high speed and heavy load cannot be met only by a service braking system (commonly called foot brake) of the vehicle. The long-time frequent brake treading can cause the temperature of the brake block to rise, the brake effect to decline and even the brake failure to endanger the safety of people and vehicles!

In order to ensure the safety performance of the vehicle, a retarder or other auxiliary braking devices must be added, and the added retarder can shunt the load of the wheel brake, so that the temperature of the wheel friction brake is controlled within a safety range. The service brake system has the function of realizing the parking under the emergency condition, can absorb great power in a short time, but the absorbed power can be greatly reduced along with the increase of the brake duration time, and finally the service brake system can not meet the emergency parking requirement of the automobile on the downhill. The retarder has the function of mainly reducing or maintaining the speed of the vehicle on a long and steep slope in a certain speed range, is not a system for stopping the vehicle, and can be normally used on a flat road to reduce the speed of the vehicle. Although the power which can be absorbed in a short time is smaller than that of service braking, the absorbed power can be basically kept unchanged for a long time, particularly in the whole downhill process, the characteristic can meet different continuous braking requirements when a vehicle continuously descends, the retarder can meet the requirements, the use frequency of foot braking can be effectively reduced, and the problems that the temperature of a friction plate is increased, the braking effect is reduced and even the braking fails due to long-time use of the brake are avoided.

The retarder is almost the same as an engine and a gearbox in developed countries abroad and becomes the standard configuration of a commercial vehicle.

China implements national standard GB7258-2012 'Motor vehicle operation safety technical regulation' on 9/1 of 2012; the quality of the national quality supervision general administration of the people's republic of China and the national standard committee in 29.9.2017 jointly release and require that 1.1.2018.1.2018 execute GB7258-2017 regulations on the safety technology for motor vehicle operation, and make explicit provisions for auxiliary brakes in 7.5: passenger cars with the car length of more than 9m (the car length is more than 8m for special school buses), trucks with the total mass of more than or equal to 12000kg, special operation vehicles, dangerous goods transportation trucks with the total mass of more than 3500kg and the like are required to be provided with a retarder or other auxiliary braking devices. The performance of the auxiliary brake device of passenger cars with the car length of more than 9m and without passenger standing areas, dangerous goods transport trucks with the total mass of more than 3500kg and semi-trailer tractor equipment is to ensure that the cars pass the type II or type II A test specified in GB 12676.

the current commercial vehicle retarder mainly comprises an eddy current retarder, a hydraulic retarder and an engine retarder. The engine retarder can be divided into an engine brake and an exhaust brake, and the engine brake is divided into a compression release type brake and an air release type brake according to different brake implementation modes.

When the engine brake is opened, the engine ECU sends an instruction of stopping oil injection to the oil injector, the engine brake piston extends out to open the brake exhaust valve, gas in the engine cylinder escapes through the opened brake exhaust valve, no fuel is combusted in the engine cylinder, and therefore the engine does not provide traction force for the vehicle any more. The vehicle drives the engine crankshaft to continue rotating through the driving wheel and the transmission belt, the kinetic energy input by the vehicle to the engine is gradually consumed in the aspects of pumping loss (power loss caused by throttling of gas in an intake stroke and an exhaust stroke) of the engine, self mechanical friction loss, irreversible loss generated in the compression and expansion processes, power loss of driving engine accessories (an oil pump, a water pump, an air compressor, a steering pump, a fan and the like), and the like, the engine which is originally a vehicle power source is changed into the air compressor which consumes the kinetic energy of the vehicle to slow the vehicle speed, or the engine does negative work at the moment, the torque of the engine for preventing the crankshaft from rotating is changed into braking torque, and the braking torque is transmitted to the driving wheel through the transmission system.

Braking oil circuit controlling means belongs to the core technology of engine brake, and its main function is when braking: sealed high-pressure oil is formed in the brake control oil way by controlling the oil way, the brake piston extends to expand a brake stroke under the action of external force (brake oil pressure, a mechanical device, air pressure or an electromagnetic mechanism), and a brake exhaust valve is opened under the driving of high brake oil pressure at the top or a cam brake stroke, so that the engine brake is realized.

At present, a brake oil path control device mainly comprises an integrated hydraulic control device and a split hydraulic control device. The integrated hydraulic control device is characterized in that a hydraulic system controlled by an electromagnetic valve is additionally arranged on an engine to form a hydraulic chain to control the opening of an exhaust valve, so that the braking function of the engine is realized, and the structure has the defects that pressure-bearing oil is always in a closed cavity in the long-term braking process, and the continuous braking effect of a brake can be influenced due to high-pressure leakage; the oil charge response speed is normal when the brake is opened. The split hydraulic control device mainly divides the oil inlet channel into two paths, which can lead to lower oil inlet pressure and low oil filling efficiency, and the overlong oil channel can lead to too long time for filling the whole oil channel, poor oil filling response speed, longer oil filling time and poorer braking sensitivity.

The brake piston belongs to the core component of an engine brake, and mainly has the main functions of extending and expanding a brake stroke under the action of external force (brake oil pressure, a mechanical device, air pressure or an electromagnetic mechanism) during braking, and opening a brake exhaust valve under the driving of high brake oil pressure at the top or a cam brake stroke, so that the engine brake is realized.

Disclosure of Invention

the invention aims to solve the technical problem of providing a hydraulic engine braking system which is stable in oil filling, high in response speed, stable and reliable in braking stroke, convenient for manual direct measurement and capable of reducing motion friction.

in order to solve the technical problems, the technical scheme of the invention is as follows: the hydraulic engine braking system comprises a supporting frame, wherein a braking control device and a braking piston device are installed on the supporting frame, the braking control device comprises a sealing piston installed in the supporting frame, a one-way valve assembly and a pressure limiting valve assembly are respectively communicated with two sides of the sealing piston in the supporting frame, a sealing piston resetting device is arranged between the sealing piston and the pressure limiting valve assembly, a braking starting oil duct is communicated between the one-way valve assembly and the sealing piston, a braking oil charging oil duct is communicated between the one-way valve assembly and the braking piston device, a releasing pressure-releasing oil duct is communicated between the braking piston device and the pressure limiting valve assembly, and the sealing piston reciprocates in the supporting frame to be communicated with and cut off the releasing pressure-releasing oil duct;

The brake piston device comprises a brake piston vertically and slidably mounted in the support frame, the bottom end of the brake piston extends out of the support frame and is in contact with a brake pin, the top of the brake piston is provided with a brake hole cavity communicated with the brake oil charging oil passage and the release pressure relief oil passage, and a brake piston resetting device is arranged between the lower part of the brake piston and the support frame.

As a preferred technical scheme, a piston starting cavity and a piston oil storage cavity are respectively arranged on two sides of the sealing piston, the piston starting cavity is communicated with the one-way valve assembly, and the piston oil storage cavity is communicated with the pressure limiting valve assembly; the brake starting oil duct is communicated with the one-way valve assembly and the sealing piston through the piston starting cavity, the release pressure-relief oil duct is communicated between the brake hole cavity and the piston oil storage cavity, and the sealing piston reciprocates in the piston starting cavity to be communicated with and cut off the release pressure-relief oil duct.

As a preferred technical scheme, the check valve assembly comprises a check ball valve which connects and disconnects the piston starting cavity and the braking oil-filled oil passage, a check valve return spring is arranged at the top end of the check ball valve, and the check valve return spring is connected to the supporting frame through a check valve plug.

as a preferred technical scheme, the pressure limiting valve assembly comprises a pressure limiting valve body fixedly mounted on the support frame, a pressure limiting ball valve for pressure relief and pressure maintaining is mounted on the pressure limiting valve body, a pressure limiting return spring for controlling the pressure limiting ball valve to open and close is arranged at the bottom end of the pressure limiting ball valve, and a pressure relief hole is formed in the pressure limiting valve body.

Preferably, the sealing piston return device comprises a sealing piston return spring connected between the sealing piston and the pressure limiting valve assembly.

As a preferred technical scheme, an adjusting bolt is installed at the top end of the supporting frame in a threaded manner, and the bottom end of the adjusting bolt is installed in the braking hole cavity; and an antifriction device is arranged on the sliding peripheral surface of the brake piston matched with the support frame.

Preferably, the friction reducing means comprises a plurality of annular grooves provided on the sliding outer peripheral surface of the brake piston.

As a preferable technical scheme, a piston sliding portion in sliding fit with the supporting frame is arranged at the upper portion of the brake piston, a piston limiting cover surrounding the brake cavity is mounted at the top end of the piston sliding portion, a piston oil inlet channel communicating the brake cavity with the brake oil-filled oil passage is arranged on the piston limiting cover, and a piston rod extending out of the supporting frame is arranged at the lower end of the brake piston.

As an optimal technical scheme, the brake piston resetting device comprises a return spring baffle arranged at the bottom of the supporting frame, a brake return spring for driving the brake piston to reset is arranged between the return spring baffle and the brake piston, and the brake return spring is sleeved outside the piston rod, and two ends of the brake return spring are respectively abutted against the return spring baffle and the piston sliding part.

As a preferred technical scheme, the upper part of the adjusting bolt is fixed on the supporting frame through a locking nut, a bolt adjusting groove which is beneficial to screwing in and screwing out is arranged at the top end of the adjusting bolt, a limiting boss which is arranged in the braking hole cavity is arranged at the bottom end of the adjusting bolt, and the outer diameter of the limiting boss is smaller than the inner diameter of the braking hole cavity; the top end of the piston limiting cover is provided with a limiting hole which limits the limiting boss in the braking hole cavity, and the limiting hole is a round hole or a long hole.

By adopting the technical scheme, the hydraulic engine braking system comprises a supporting frame, wherein a braking control device and a braking piston device are arranged on the supporting frame, the brake control device comprises a sealing piston arranged in the supporting frame, a one-way valve assembly and a pressure limiting valve assembly are respectively communicated with two sides of the sealing piston in the supporting frame, a sealing piston resetting device is arranged between the sealing piston and the pressure limiting valve assembly, a brake starting oil duct is communicated between the one-way valve assembly and the sealing piston, a brake oil charging oil passage is communicated between the one-way valve assembly and the brake piston device, a release pressure relief oil passage is communicated between the brake piston device and the pressure limiting valve assembly, the sealing piston reciprocates in the supporting frame to communicate with and cut off the release pressure relief oil passage;

the brake piston device comprises a brake piston vertically and slidably mounted in the support frame, the bottom end of the brake piston extends out of the support frame and is in contact with a brake pin, the top of the brake piston is provided with a brake hole cavity communicated with the brake oil charging oil passage and the release pressure relief oil passage, and a brake piston resetting device is arranged between the lower part of the brake piston and the support frame; the invention has the beneficial effects that:

(1) The pressure of the brake oil during release can be controlled by adjusting the oil drainage pressure of the pressure limiting valve assembly, so that the phenomenon that the brake oil is completely released to cause overlong oil filling time during the next braking is prevented; the storage of the brake oil is realized through the action of the pressure limiting valve assembly, the brake oil way can be assisted to be filled more quickly during the next braking, and the brake oil way has the advantages of stable oil filling, high response speed, high brake sensitivity and the like;

(2) Adjusting the clearance between the brake piston and the brake pin, namely the brake valve clearance, by rotating the adjusting bolt, so as to meet different use requirements;

(3) The maximum clearance between the lower bottom surface of the piston limiting cover and the upper top surface of the limiting boss is the maximum braking stroke of the piston limiting cover, the braking stroke of the piston limiting cover is stable and reliable, manual direct measurement is facilitated, the measurement difficulty is reduced, and the measurement efficiency is improved;

(4) The annular groove on the outer peripheral surface of the brake piston has the functions of storing oil and containing impurities carried in engine oil, so that the motion abrasion between the brake piston and the supporting frame is reduced, the service life of the brake piston is prolonged, and the brake accuracy is improved;

(5) The braking return spring is sleeved at the outer end of the piston rod, hydraulic oil cannot contact the braking return spring when working, the working environment of the braking return spring is good, the service life of the braking return spring can be effectively guaranteed, and compared with the prior art, the braking return spring has a better return effect and a better braking effect.

drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention.

Wherein:

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a brake control apparatus according to an embodiment of the present invention in a non-braking state;

FIG. 3 is a schematic structural view of a brake piston assembly according to an embodiment of the present invention in a non-braking state;

FIG. 4 is an enlarged view of the brake piston assembly of the present invention in a non-braking condition;

FIG. 5 is a schematic structural view of the brake control apparatus according to the embodiment of the present invention;

FIG. 6 is a schematic structural view of a brake piston assembly according to an embodiment of the present invention;

FIG. 7 is an enlarged view of the brake piston assembly of the embodiment of the present invention during braking;

in the figure: 1-a support frame; 2-a brake control device; 21-a sealing piston; 22-a one-way valve assembly; 221-one-way ball valve; 222-a one-way valve return spring; 223-blocking a one-way valve; 23-a pressure limiting valve assembly; 231-a pressure limiting valve body; 232-pressure limiting ball valve; 233-pressure limiting return spring; 234-pressure relief vent; 24-a brake actuation oil passage; 25-brake oil charge oil duct; 26-releasing the pressure relief oil passage; 27-a piston actuation chamber; 28-piston oil reservoir; 29-sealing piston return spring; 3-braking the piston device; 31-a brake piston; 311-piston sliding part; 312-piston limit cap; 313 — piston oil intake channel; 314-a piston rod; 32-a brake bore; 33-brake piston resetting means; 331-return spring retainer; 332-braking the return spring; 34-adjusting bolts; 341-lock nut; 342-bolt adjustment slots; 343-limit boss; 344-a limiting hole; 35-an annular groove; 4-a brake pin; and 5-an exhaust valve.

Detailed Description

The invention is further illustrated below with reference to the figures and examples. In the following detailed description, certain exemplary embodiments of the present invention are described by way of illustration only. Needless to say, a person skilled in the art realizes that the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are illustrative in nature and not intended to limit the scope of the claims.

As shown in fig. 1 to 7, the hydraulic engine braking system includes a supporting frame 1, the supporting frame 1 includes but is not limited to a rocker arm mechanism, a moving part or a fixing part, a braking control device 2 and a braking piston device 3 are installed on the supporting frame 1, referring to fig. 2 and 5, the braking control device 2 includes a sealing piston 21 slidably installed in the supporting frame 1, a check valve assembly 22 and a pressure limiting valve assembly 23 are respectively communicated with two sides of the sealing piston 21 in the supporting frame 1, a sealing piston resetting device is arranged between the sealing piston 21 and the pressure limiting valve assembly 23, a braking start oil passage 24 is communicated between the check valve assembly 22 and the sealing piston 21, a braking oil-filled oil passage 25 is communicated between the check valve assembly 22 and the braking piston device 3, a release oil passage 26 is communicated between the braking piston device 3 and the pressure limiting valve assembly 23, the sealing piston 21 reciprocates in the support frame 1 to communicate with and cut off the relief pressure oil passage 26.

Referring to fig. 2 and 5, a piston starting cavity 27 and a piston oil storage cavity 28 are respectively arranged on two sides of the sealing piston 21, the piston starting cavity 27 is communicated with the one-way valve assembly 22, and the piston oil storage cavity 28 is communicated with the pressure limiting valve assembly 23; the brake starting oil passage 24 is communicated with the one-way valve assembly 22 and the sealing piston 21 through the piston starting cavity 27, the release pressure relief oil passage 26 is communicated between a brake hole cavity 32 of the brake piston device 3 and the piston oil storage cavity 28, and the sealing piston 21 is communicated with and cuts off the release pressure relief oil passage 26 in a reciprocating motion mode in the piston starting cavity 27.

referring to fig. 2 and 5, the check valve assembly 22 includes a check ball valve 221 for connecting and disconnecting the piston actuation cavity 27 and the brake oil-filled oil passage 25, a check valve return spring 222 is disposed at a top end of the check ball valve 221, and the check valve return spring 222 is connected to the support frame 1 through a check valve plug 223. The check valve assembly 22 has a one-way flow function, so that the brake oil in the piston starting cavity 27 can enter the brake oil charging oil passage 25, but the brake oil in the brake oil charging oil passage 25 cannot flow back to the piston starting cavity 27.

Referring to fig. 2 and 5, the pressure limiting valve assembly 23 includes a pressure limiting valve body 231 fixedly installed on the support frame 1, a pressure limiting ball valve 232 for pressure relief and pressure maintaining is installed on the pressure limiting valve body 231, a pressure limiting return spring 233 for controlling the opening and closing of the pressure limiting ball valve 232 is installed at the bottom end of the pressure limiting ball valve 232, a pressure relief hole 234 is installed on the pressure limiting valve body 231, when the pressure limiting ball valve 232 is opened, the piston oil storage cavity 28 is communicated with the pressure relief hole 234, and the brake oil in the piston oil storage cavity 28 can be discharged through the pressure relief hole 234. The designer selects the pressure-limiting return spring 233 according to actual use requirements, and the pressure-limiting return spring is used for controlling the closing pressure of the pressure-limiting ball valve 232, namely, the pressure which can be reached in the piston oil storage cavity 28 when the pressure-limiting ball valve 232 is closed is controlled, so that when the pressure-limiting ball valve 232 is closed, a part of brake oil can be stored in the piston oil storage cavity 28, but the movement of the sealing piston 21 when the next brake is started is not influenced.

Referring to fig. 2 and 5, the sealing piston return means comprises a sealing piston return spring 29 connected between the sealing piston 21 and the pressure limiting valve assembly 23.

The operating principle of the brake control device 2 is as follows:

When the brake is not applied: the brake starting oil passage 24 has no engine oil pressure, at this time, the sealing piston 21 is kept at the top dead center position under the action of the sealing piston return spring 29, the one-way ball valve 221 and the pressure limiting ball valve 232 are both in a closed state, and the release pressure relief oil passage 26 between the brake piston device 3 and the piston oil storage cavity 28 is communicated, and the state is shown in fig. 2.

During braking: engine oil enters the piston starting cavity 27 through the brake starting oil passage 24 on the support frame 1, and simultaneously acts on the one-way ball valve 221 and the sealing piston 21, referring to fig. 3, the spring force of the one-way valve return spring 222 is overcome to push the one-way ball valve 221 to open, and lubricating oil or brake oil enters the brake piston device 3 through the brake oil filling oil passage 25, so that the brake piston is fully extended, namely, the maximum stroke of the brake piston is realized, and simultaneously, the pre-tightening force of the sealing piston return spring 29 is overcome to push the sealing piston 21 to move to the upper end surface of the pressure limiting valve assembly 23, so that the release pressure relief oil passage 26 between the brake piston device 3 and the piston oil storage cavity 28 is cut off and the release pressure relief oil passage 26 is sealed; after the brake oil entering the brake piston device 3 is filled, the sum of the pressure in the brake oil charging oil passage 25 and the spring force of the one-way valve return spring 222 is greater than the pressure in the piston starting cavity 27, so that the one-way ball valve 221 returns and seals, and due to the incompressible characteristic of liquid, the brake oil charging oil passage 25, the release pressure relief oil passage 26 and the brake piston device 3 form high pressure when the brake piston receives the counter-acting force of a valve.

when braking stops: when braking is not needed any more, the brake starting oil passage 24 communicated into the piston starting cavity 27 is cut off, so that the pressure for pushing the sealing piston 21 disappears, the sealing piston 21 returns under the action of the sealing piston return spring 29, then the release pressure relief oil passage 26 is communicated with the piston oil storage cavity 28, engine oil is pressed into the piston oil storage cavity 28 through the release pressure relief oil passage 26, when the oil pressure is greater than the spring force of the pressure limiting return spring 233, the brake oil pushes the pressure limiting ball valve 232 to be discharged through the pressure relief hole 234, the brake piston of the brake piston device 3 starts to return, and the brake piston is reset to be completed. When piston oil storage chamber 28 pressure with the spring force of pressure limiting return spring 233 reaches the equilibrium, pressure limiting ball valve 232 closes, piston oil outlet intracavity will remain some brake oil and not leak completely, and when carrying out next braking process, entire system will no longer need add more brake oil, only need add a small amount of brake oil, just can make piston arresting gear's brake piston realize the braking, remains the brake oil in piston oil storage chamber 28 can be convenient for next braking process and realize quick oil-charging, state when sealing piston 21 lets out the pressure refers to fig. 2. The pressure of the brake oil during release can be controlled by adjusting the oil drainage pressure of the pressure limiting valve assembly 23, so that the phenomenon that the brake oil is completely released to cause the overlong time of filling the brake oil during the next braking is prevented; and the storage of the brake oil is realized through the action of the pressure limiting valve assembly 23, the brake oil way can be assisted to be filled more quickly during the next braking, and the brake oil way has the advantages of stable oil filling, high response speed, high brake sensitivity and the like.

referring to fig. 3, 4, 6 and 7, the brake piston device 3 includes a brake piston 31 vertically slidably mounted in the support frame 1, and when the brake piston 31 extends, the brake piston drives a brake pin 4 to open a brake exhaust valve 5, a bottom end of the brake piston 31 extends out of the support frame 1 to contact with the brake pin 4, a brake bore 32 communicating with the brake oil-filled oil passage 25 and the release oil passage 26 is disposed at a top of the brake piston 31, and a brake piston resetting device 33 is disposed between a lower portion of the brake piston 31 and the support frame 1.

referring to fig. 3, 4, 6 and 7, the top end of the supporting frame 1 is provided with a threaded hole, an adjusting bolt 34 is internally threaded in the threaded hole, the bottom end of the adjusting bolt 34 is installed in the braking hole cavity 32, and the braking hole cavity 32 limits the bottom end of the adjusting bolt 34 in the braking hole cavity 32, so that the braking piston 31 cannot be disengaged from the bottom end of the adjusting bolt 34 when the braking piston 31 moves up and down; and an antifriction device is arranged on the sliding peripheral surface of the brake piston 31 matched with the support frame 1.

Referring to fig. 3, 4, 6 and 7, the friction reducing means includes a plurality of annular grooves 35 provided on the sliding outer circumferential surface of the brake piston 31. In this embodiment, be provided with two ring channels 35 on the activity peripheral face of brake piston 31, ring channel 35 has the effect of depositing oil and holding the impurity that carries in the engine oil, brake piston 31 up-and-down motion in-process, hydraulic oil can be stored in ring channel 35 to reduce brake piston 31 with the motion friction between braced frame 1, when impurity exists, impurity can be restricted in the ring channel 35, avoid right brake piston 31 with cause the motion wearing and tearing between braced frame 1, the jamming phenomenon appears, has not only improved brake piston 31's life, but also has improved the braking reliability.

Referring to fig. 3, 4, 6 and 7, the upper portion of the brake piston 31 is provided with a piston sliding portion 311 slidably engaged with the support frame 1, and the annular groove 35 is provided on the sliding outer circumferential surface of the piston sliding portion 311 to reduce the kinetic wear between the piston sliding portion 311 and the support frame 1; the top end of the piston sliding part 311 is provided with a piston limiting cover 312 which surrounds the brake cavity 32, the piston limiting cover 312 is provided with a piston oil inlet channel 313 which communicates the brake cavity 32 with the brake oil-filled oil channel 25, the piston oil inlet channel 313 is arranged to ensure that engine oil from the brake oil-filled oil channel 25 can smoothly enter the brake cavity 32, the lower end of the brake piston 31 is provided with a piston rod 314 which extends out of the support frame 1, and the bottom end of the piston rod 314 is contacted with the brake pin 4.

Referring to fig. 3, 4, 6 and 7, the brake piston returning device 33 includes a return spring retainer 331 installed at the bottom of the supporting frame 1, a brake return spring 332 for driving the brake piston 31 to return is installed between the return spring retainer 331 and the brake piston 31, the brake return spring 332 is sleeved outside the piston rod 314, and two ends of the brake return spring respectively abut against the return spring retainer 331 and the piston sliding portion 311. During braking, hydraulic oil from the brake oil-filled oil passage 25 enters the brake hole cavity 32, the oil pressure in the brake hole cavity 32 is increased, the brake piston 31 is pushed to move downwards against the spring force of the brake return spring 332, after braking is finished, the hydraulic oil is discharged from the release pressure relief oil passage 26, the oil pressure in the brake hole cavity 32 is reduced, and the brake return spring 332 can push the brake piston 31 to move upwards for resetting; in this embodiment, the braking return spring 332 is sleeved at the outer end of the piston rod 314, is not in contact with the support frame 1, and is not connected with the braking hole cavity 32, the hydraulic oil in the braking hole cavity 32 is not in contact with the braking return spring 332, the working environment of the braking return spring 332 is good, the service life of the braking return spring 332 can be effectively ensured, and compared with the prior art, the braking return spring 332 has a better resetting effect and a better braking effect.

referring to fig. 3, 4, 6 and 7, the upper portion of the adjusting bolt 34 is fixed to the support frame 1 by a locking nut 341, a bolt adjusting groove 342 facilitating screwing in and screwing out is provided at the top end of the adjusting bolt 34, a limiting boss 343 installed in the brake bore 32 is provided at the bottom end of the adjusting bolt 34, the outer diameter of the limiting boss 343 is smaller than the inner diameter of the brake bore 32, that is, the bottom end area of the brake bore 32 is larger than the bottom end area of the limiting boss 343, and a gap L1 is left therebetween, so that engine oil entering the brake bore 32 can be ensured to directly contact the bottom end of the brake bore 32, thereby pushing the brake piston 31 downward more easily and improving the operation sensitivity of the brake piston 31.

Referring to fig. 3, 4, 6 and 7, a limit hole 344 for limiting the limit boss 343 in the brake hole cavity 32 is disposed at the top end of the piston limit cover 312, the limit hole 344 is a circular hole or a long hole, in this embodiment, the limit hole 344 is a circular hole, the inner diameter of the limit hole 344 is larger than the outer diameter of the adjusting bolt 34 and smaller than the outer diameter of the limit boss 343, and the inner diameter of the limit hole 344 is larger than the outer diameter of the adjusting bolt 34, so that when the piston limit cover 312 can move up and down along the adjusting bolt 34 and a gap is formed between the outer diameter of the adjusting bolt 34 and the inner diameter of the limit hole 344, hydraulic oil can enter the brake hole cavity 32, where the gap between the outer diameter of the adjusting bolt 34 and the inner diameter of the limit hole 344 is the piston oil inlet channel 313; the outer diameter of the limit boss 343 is larger than the inner diameter of the limit hole 344 to ensure that the limit boss 343 is restricted within the brake bore 32 to ensure that the maximum stroke of the brake piston 31 is always S. When the lower bottom surface of the limit boss 343 contacts the bottom surface of the brake bore 32, the maximum clearance between the lower bottom surface of the piston limit cover 312 and the upper top surface of the limit boss 343 is the maximum brake stroke S of the brake piston 31 or the brake piston device 3, and when the brake stroke is 0, the lower bottom surface of the piston limit cover 312 and the upper top surface of the brake piston 31 are fitted. The maximum gap between the lower bottom surface of the piston limit cover 312 and the upper top surface of the limit boss 343 is the maximum brake stroke S of the present invention, which is stable and reliable, and facilitates direct manual measurement, reduces measurement difficulty, and improves measurement efficiency.

the top end of the adjusting bolt 34 is provided with a bolt adjusting groove 342 which is beneficial to screwing in and screwing out, and the bolt adjusting groove 342 is arranged to facilitate the rotation adjustment of tools such as a screwdriver or a screwdriver and the like.

The working principle of the brake piston device 3 is as follows:

When the brake is not applied: when the brake control device 2 is not in operation, the engine oil pressure does not exist in the brake oil-filled oil passage 25, the cold brake valve clearance L of the engine is adjusted by rotating the adjusting bolt 34, and the bottom surface of the brake cavity 32 is tightly attached to the lower bottom surface of the limit boss 343 under the action of the return spring baffle 331 and the brake return spring 332, as shown in fig. 3 and 4.

When the brake is started: engine oil enters the brake oil-filled oil passage 25 through the brake control device 2, then enters the brake bore 32 through the piston oil inlet passage 313 on the piston limit cover 312, oil pressure is generated in the brake bore 32, the brake piston 31 is pushed to move downwards against the spring force of the brake return spring 332, and when the upper top surface of the limit boss 343 contacts with the lower bottom surface of the piston limit cover 312, the brake piston 31 finishes extending, namely, the maximum stroke S of the brake piston 31 is realized. The brake piston 31 contacts with the brake pin 4 after extending, engine oil in the brake cavity 32 is compressed into high-pressure oil under the action of the reaction force of the brake exhaust valve 5 and the brake control device 2, the brake exhaust valve 5 is opened in combination with the brake stroke of the brake piston 31 or the brake lift of the cam, and engine braking is achieved, and the extended state of the brake piston 31 is shown in fig. 6 and 7.

When braking is finished: when braking is no longer needed, the brake oil is discharged from the relief oil passage 26, so that the pressure pushing the brake piston 31 disappears, the brake piston 31 is reset under the action of the brake return spring 332, the lower bottom surface of the piston limit cover 312 is no longer in contact with the upper top surface of the limit boss 343, but the bottom surface of the brake bore 32 is in contact with the lower bottom surface of the limit boss 343 under the action of the brake return spring 332, see fig. 3 and 4.

Valve clearance adjustment principle: when the valve clearance needs to be adjusted, the adjusting bolt 34 is screwed downwards, the adjusting bolt 34 drives the limiting boss 343 to move downwards, and then the brake piston 31 is pushed downwards to move downwards, at this time, the maximum brake stroke between the limiting boss 343 and the brake bore 32 is unchanged and is still S, but the valve clearance between the brake piston 31 and the brake pin 4 is reduced, the adjustment range of the valve clearance is L in fig. 3, and when the brake piston 31 gradually moves downwards, the valve clearance L is gradually reduced.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.